Segment Information - Geographic Information (Details) $ in Millions	12 Months Ended
Dec. 31, 2018 USD ($) customer	Dec. 31, 2017 USD ($) customer	Dec. 31, 2016 USD ($) customer
Segment Information
Revenue	$ 79,591	$ 79,139	$ 79,919
Net property, plant and equipment	10,792	11,116
Plant and other property
Segment Information
Net property, plant and equipment	$ 10,359	$ 10,655	$ 10,308
Revenue \| Major Client
Segment Information
Number of clients representing 10% or more of the company's total revenue \| customer	0	0	0
U.S. \| Revenue \| Geographic Information
Segment Information
Revenue	$ 29,078	$ 29,759	$ 30,194
U.S. \| Revenue \| Geographic Information \| Minimum
Segment Information
Concentration Risk, Percentage	10.00%	10.00%	10.00%
U.S. \| Plant and Other Property - Net \| Geographic Information \| Minimum
Segment Information
Concentration Risk, Percentage	10.00%	10.00%	10.00%
U.S. \| Plant and Other Property - Net \| Geographic Information \| Plant and other property
Segment Information
Net property, plant and equipment	$ 4,585	$ 4,670	$ 4,701
Japan \| Revenue \| Geographic Information
Segment Information
Revenue	$ 8,489	$ 8,239	$ 8,339
Japan \| Revenue \| Geographic Information \| Minimum
Segment Information
Concentration Risk, Percentage	10.00%	10.00%	10.00%
Other Countries \| Revenue \| Geographic Information
Segment Information
Revenue	$ 42,024	$ 41,141	$ 41,386
Non-U.S. \| Plant and Other Property - Net \| Geographic Information \| Plant and other property
Segment Information
Net property, plant and equipment	$ 5,774	$ 5,985	$ 5,607

The number of customers that individually represent 10 percent or more of the company's total revenue.

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Amount after accumulated depreciation, depletion and amortization of physical assets used in the normal conduct of business to produce goods and services and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, and furniture and fixtures.

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Amount of revenue recognized from goods sold, services rendered, insurance premiums, or other activities that constitute an earning process. Includes, but is not limited to, investment and interest income before deduction of interest expense when recognized as a component of revenue, and sales and trading gain (loss).

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